1. Field of the Invention
The present invention relates to controllers for a video game machine. In particular, the present invention relates to expandable controllers for a video game machine. More particularly, the present invention relates to expandable controllers which are series-connected for a video game machine without having to change the architecture of the video game machine.
2. Description of Prior Art
Video game machines are popular with today's families. As shown in FIG. 1, a video game machine generally includes a control deck 10 provided With two adapters 11 and 12 for two controllers 21 and 22. A game cassette (not shown) is typically connected to the control deck 10 for storing programs and data of a video game. Normally, there are only two adapters 11 and 12 for the controllers 21 and 22 provided on the control deck 10 because of the initial cost. That is, a video game machine is generally designed for two players at most. If more than two players want to play the video game machine at the same time, it is necessary to additionally connect a controller expansion unit 30 to the control deck 10 of the video game machine, as shown in FIG. 2. Controller expansion unit 30 is connected to the adapter 11 of the control deck 10. A plurality of controllers 23-25 can then be connected to the control deck 10 by means of the controller expansion unit 30. The use of an expansion unit requires that customers spend additional money to buy a controller expansion unit when they want to play a video game with more than two players. However, if the controller expansion unit 30 can only accommodate a limited number of controllers, customers must then buy another controller expansion unit with a larger capacity to overcome this limitation. These expansion problems can reduce the willingness customers to purchase a video game machine.